In medical, chemical and biological laboratories, microtiter plates are commonly used and are filled with various media. The media may either be in a liquid form, or in a more viscous form such as Agar. For efficient productivity of the laboratory, the use of a robotic device to move the microplates between locations is desirable. Such automated machines can produce considerably greater throughput than a technician. To this end there are several automated devices that are currently available to effect such transportation.
Traditionally, an articulated or cylindrical automated machine with three degrees of motion has been used. Such automated machines are often mounted on a substantially long linear axis and are moved through the entire system to load a plate from one instrument to another. Also, in more complicated systems, conveyors with escapements and slides are used as part of the system to move an object between spaced locations.
One of the disadvantages of these automated machines is that each requires a minimum of three axes of motion to transfer an object such as a microtiter plate. Typically, such machines require three to six motors to obtain the movement required at the various joints. During movement of an object between locations it is frequently necessary to maintain a fixed orientation for the object, such as maintaining a microtiter plate in a horizontal plane. On traditional machines, plate leveling is accomplished by means of a servomotor controlling an additional joint. This requires additional control functions and mechanical complexity.
In order to pass signals between the automated machine's motor and the controller, a flexible wire harness is often used, while another solution involves the use of conductive rings with metal brushes that slide along the rings to replace wire harnesses. A wire harness is susceptible to mechanical fatigue and failure, and takes a certain amount of space in the design. The drawbacks of using brushes and rings are that noise and sparks are generated by the brushes, and the mechanism requires regular maintenance. Typically, the above solutions involve substantially complex systems having a substantial number of parts requiring maintenance.
It is thus an object of this invention to obviate or mitigate at least one of the above mentioned drawbacks.